Operations Midterm

Measure Instruments of quality costs. Identifying quality problems and causes.

Mission Statements and Strategy formulation

The basics of the Statistical Process Control. Statistical Process Control in TQM. Quality measures: attributes and variables

Control Charts for attributes in TQM and Excercices.

Control Charts for variables in TQM and Excercices.

The stages of the Design Process for

products.

Functional Design: Excercises on Reliability and Serviceability

The Service design Process: steps and characteristics of services

Midterm Study Guide: Quality Management and Statistical Process Control

1. Measuring Instruments of Quality Costs

• Quality Costs Categories:

  • Prevention Costs: Costs incurred to prevent defects, such as quality training, supplier certification, process improvements, and preventive maintenance.

  • Appraisal Costs: Costs associated with measuring and monitoring quality, including inspections, audits, testing, and quality assessments.

  • Internal Failure Costs: Costs arising from defects found before products reach the customer, including rework, scrap, and downtime.

  • External Failure Costs: Costs due to defects discovered after delivery, such as warranty claims, returns, product recalls, and reputational damage.

• Measuring Quality Costs:

  • Cost-benefit analysis to compare prevention versus failure costs.

  • Pareto Analysis to identify the most significant cost contributors.

  • Benchmarking against industry standards.

  • Continuous monitoring of cost trends.

2. Identifying Quality Problems and Causes

• Tools for Identifying Quality Issues:

  • Fishbone Diagram (Ishikawa/Cause-and-Effect Diagram): Helps pinpoint root causes of quality problems.

  • Pareto Analysis: Identifies the most frequent causes of defects.

  • Histogram: Displays defect distribution patterns.

  • Check Sheets: A simple data collection tool for tracking defects.

  • Scatter Diagrams: Analyzes correlations between variables.

  • Flowcharts: Visualizes process steps and identifies inefficiencies.

  • Failure Mode and Effects Analysis (FMEA): Evaluates risks and prioritizes corrective actions.

• Common Causes of Quality Problems:

  • Poor design, inadequate training, defective materials, process variations, and human error.

3. Mission Statements and Strategy Formulation

• Mission Statement:

  • Defines an organization's purpose, values, and direction.

  • Should align with customer expectations and quality commitment.

• Strategy Formulation for Quality:

  • SWOT Analysis: Identifies strengths, weaknesses, opportunities, and threats.

  • TQM Integration: Embeds quality principles across the organization.

  • KPIs and Continuous Improvement: Uses metrics and Kaizen approaches for sustained improvement.

4. Basics of Statistical Process Control (SPC)

• Definition:

  • A method for monitoring and controlling quality using statistical techniques.

• Key Elements:

  • Understanding process variations (common vs. special causes).

  • Use of control charts to monitor stability.

  • Process capability analysis (Cp, Cpk) to assess process performance.

  • Sampling techniques for quality assessment.

5. Statistical Process Control in TQM

• Role in Total Quality Management (TQM):

  • Enhances quality through data-driven decision-making.

  • Identifies trends and areas needing improvement.

  • Minimizes variability and defects.

• Implementation Steps:

  • Data collection and analysis.

  • Selection of appropriate control charts.

  • Continuous monitoring and corrective action.

6. Quality Measures: Attributes and Variables

• Attribute Data (Qualitative):

  • Binary measures (pass/fail, defective/non-defective).

  • Examples: Number of defects per unit, error rates.

• Variable Data (Quantitative):

  • Continuous measures (length, weight, temperature, etc.).

  • Example: Measuring product dimensions to check tolerance compliance.

7. Control Charts for Attributes in TQM

• Types of Attribute Control Charts:

  • p-chart: Proportion of defective units in a sample.

  • np-chart: Number of defective items in a fixed sample.

  • c-chart: Number of defects per unit.

  • u-chart: Defects per unit with varying sample sizes.

• Exercises:

  • Calculate control limits and plot p-charts.

  • Interpret process stability and out-of-control signals.

8. Control Charts for Variables in TQM

• Types of Variable Control Charts:

  • X̄-chart: Monitors changes in process mean.

  • R-chart: Monitors variability within a sample.

  • s-chart: Tracks standard deviation over time.

• Exercises:

  • Compute X̄ and R chart values.

  • Identify trends and process variations.

9. Stages of the Design Process for Products

• Stages:

  • Concept development (idea generation, feasibility study).

  • System-level design (establishing architecture and interfaces).

  • Detail design (finalizing product specifications and materials).

  • Testing and refinement (prototyping and validation).

  • Production and launch (manufacturing and market release).

• Quality Considerations:

  • Design for Manufacturability (DFM) to optimize production efficiency.

  • Design for Six Sigma (DFSS) for defect minimization.

  • Reliability and maintainability engineering.

10. Functional Design: Reliability and Serviceability

• Reliability:

  • The probability that a product performs without failure over time.

  • Reliability calculations using Mean Time Between Failures (MTBF).

• Serviceability:

  • Designing products for ease of maintenance and repairs.

• Exercises:

  • Construct reliability block diagrams.

  • Compute system reliability for different configurations.

11. The Service Design Process

• Steps in Service Design:

  • Identifying customer expectations.

  • Conceptualizing and designing service features.

  • Service blueprinting to visualize the process.

  • Prototyping and testing for optimization.

  • Implementation and continuous evaluation.

• Characteristics of Services:

  • Intangibility: Services cannot be stored or touched.

  • Inseparability: Production and consumption occur simultaneously.

  • Variability: Service quality depends on provider consistency.

  • Perishability: Services cannot be inventoried.

• Key Service Quality Metrics:

  • SERVQUAL Model: Measures tangibles, reliability, responsiveness, assurance, and empathy.

Conclusion

This study guide provides an overview of essential topics for your midterm. Review theoretical concepts, practice exercises, and understand how SPC tools apply to quality management.

Midterm Practice Test: Quality Management and Statistical Process Control

Multiple Choice Questions

1. Which of the following is NOT a category of quality costs? a) Prevention costs
   b) Appraisal costs
   c) Marketing costs
   d) External failure costs
   Answer: c) Marketing costs

2. Which tool is used to identify root causes of quality problems? a) Pareto Chart
   b) Fishbone Diagram
   c) Control Chart
   d) Histogram
   Answer: b) Fishbone Diagram

3. What is the primary purpose of a mission statement? a) To define an organization's financial goals
   b) To outline an organization’s purpose and values
   c) To develop statistical control charts
   d) To assess process capability
   Answer: b) To outline an organization’s purpose and values

4. Which of the following best describes Statistical Process Control (SPC)? a) A method for setting organizational goals
   b) A technique for monitoring and controlling quality using statistics
   c) A marketing strategy to improve sales
   d) A way to ensure 100% defect-free products
   Answer: b) A technique for monitoring and controlling quality using statistics

5. What is the difference between attribute and variable data? a) Attribute data is continuous, while variable data is categorical
   b) Attribute data measures defects, while variable data measures continuous characteristics
   c) Variable data is qualitative, while attribute data is quantitative
   d) Both attribute and variable data measure pass/fail outcomes
   Answer: b) Attribute data measures defects, while variable data measures continuous characteristics

6. Which control chart is used to monitor the proportion of defective units in a sample? a) X̄-chart
   b) p-chart
   c) R-chart
   d) s-chart
   Answer: b) p-chart

7. In the design process, what comes after concept development? a) Detail design
   b) System-level design
   c) Production and launch
   d) Testing and refinement
   Answer: b) System-level design

8. What does the SERVQUAL model measure? a) Manufacturing efficiency
   b) Process capability
   c) Service quality based on customer expectations
   d) Equipment maintenance schedules
   Answer: c) Service quality based on customer expectations

True/False Questions

9. TQM focuses only on detecting and correcting defects after production.
   False (TQM emphasizes continuous improvement and defect prevention)

10. A control chart helps identify whether a process is in a state of statistical control.
    True

11. Prevention costs include warranty claims and product recalls.
    False (These are external failure costs)

12. In SPC, special cause variation is expected and part of normal process operation.
    False (Special cause variation indicates an issue that requires correction)

13. The reliability of a product is measured using Mean Time Between Failures (MTBF).
    True

14. Services differ from products because they are tangible and can be stored for later use.
    False (Services are intangible and cannot be stored)